Any hints on how to find the current battery status of an Apple Magic Keyboard on Linux?

I have an Apple Magic Keyboard connected over bluetooth:

[Magic Keyboard]# info
Device 2C:33:61:E5:1A:F8 (public)
	Name: Magic Keyboard
	Alias: Magic Keyboard
	Class: 0x00000540
	Icon: input-keyboard
	Paired: yes
	Trusted: yes
	Blocked: no
	Connected: yes
	WakeAllowed: no
	LegacyPairing: no
	UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)
	UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
	Modalias: bluetooth:v004Cp0267d0100

After an hour or so of Googling and experimenting I am giving up and asking for help.

I’m guessing that battery status is part of the Bluetooth standard, so Linux should be able to know the current battery percentage of the Magic Keyboard, I just have no idea where to look.


What I have tried:

❯ upower --dump     
Device: /org/freedesktop/UPower/devices/DisplayDevice
  power supply:         no
  updated:              Fri 23 Oct 2020 02:02:26 PM CEST (125419 seconds ago)
  has history:          no
  has statistics:       no
  unknown
    warning-level:       none
    icon-name:          'battery-missing-symbolic'

Daemon:
  daemon-version:  0.99.11
  on-battery:      no
  lid-is-closed:   no
  lid-is-present:  no
  critical-action: PowerOff

No Magic Keyboard there.

❯ ls /sys/class/power_supply 
hidpp_battery_1

No Magic Keyboard there either, that’s my wireless Logitech mouse.